Technical Field
Various embodiments described herein generally relate to circuit simulation and, more particularly, to a Laplace transform system simulation method and apparatus.
Related Art
With the fast developments in semiconductor manufacturing and acute requirements for more advanced product functions, integrated circuits (ICs) have become too complex for engineers to design by specifying each individual transistor and wire. To facilitate circuit design, behavioral blocks, which enable designers to capture high-level behavioral descriptions of components of an IC in a set of mathematical terms, are widely used in a top-down mixed-signal simulator. For example, the behavioral blocks may be defined to describe the analog behavior of one or more components in an IC. During simulation, all analog blocks are evaluated by converting complex equations into simpler ones. The complex equation, which may take the form of a high-order Laplace transfer function, exhibits a set of component characteristics and/or behavior in an IC.
Laplace transform components are widely used in radio frequency (RF) design, including Laplace transform filters described in Verilog-A or VHDL-AMS (Very high speed integrated circuits Hardware Description Language-Analog-Mixed Signal) language, or s-domain sources in the CMI (Compiled Model Interface), like svcvs (s-domain voltage controlled voltage source) or sccvs (s-domain current controlled voltage source). As to behavioral blocks, designers only need to focus on component's characteristics and behavior, and need not pay attention to detailed information on internal structure of a circuit. However, as system order and frequency become higher, accumulation of dynamic range of a difference equation set becomes more severe, which leads to accuracy and convergence problems when applying numerical methods for simulation. The issue with the accumulation of dynamic range has existed for several years. Nevertheless, no effective solution has been proposed to address the issue.
It may therefore be desirable to provide a method and an apparatus to alleviate the dynamic range issue.